Heretofore, polytetrahydrofuran-toluene diisocyanate prepolymers were readily cured with metal halide salt complexes of methylenedianiline, generally dispersed in a plasticizer. However, cure with polyether intermediates having substituted alkyl oxyethylene repeating units was rather slow and yielded end products having poor physical properties.
U.S. Pat. No. 3,755,261 to VanGulick relates to the use of metal halide salt complexes of methylenedianiline in the cure of urethane polymers.
U.S. Pat. No. 4,330,454 to Kimball relates to a storable, flowable polypropylene ether urethane composition having a relatively long shelf life which is made by reacting polypropylene ether glycol with MDI and cure with metal halide salt complexes of MDA.
U.S. Pat. No. 4,463,155 to Kibler relates to a polyurethane-urea derived from the reaction of a polyether diol such as polytetrahydrofuran diol with a polyether diisocyanate prepolymer with simultaneous chain extension utilizing a metal halide salt complex of MDA.
U.S. Pat. No. 4,517,331 to Parker et al, relates to a storable polypropylene ether polyurethane composition made from a prepolymer of a polypropylene ether glycol and an organic polyisocyanate which is cured with metal halide salt complexes of MDA in association with a crown or pseudocrown ether catalysts.
The above patents failed to recognize that ethylene oxide units contained in a polyether intermediate having ethylene oxide units therein would increase the reactivity of the prepolymers made therefrom with metal halide salt complexes of MDA.